former is callable from user space and the latter from the kernel one. Make
kernel version take additional argument which tells if the respective call
should check for additional restrictions for sending signals to suid/sugid
applications or not.
Make all emulation layers using non-checked version, since signal numbers in
emulation layers can have different meaning that in native mode and such
protection can cause misbehaviour.
As a result remove LIBTHR from the signals allowed to be delivered to a
suid/sugid application.
Requested (sorta) by: rwatson
MFC after: 2 weeks
the semantics in that the returned filename to use is now a kernel
pointer rather than a user space pointer. This required changing the
arguments to the CHECKALT*() macros some and changing the various system
calls that used pathnames to use the kern_foo() functions that can accept
kernel space filename pointers instead of calling the system call
directly.
- Use kern_open(), kern_access(), kern_execve(), kern_mkfifo(), kern_mknod(),
kern_setitimer(), kern_getrusage(), kern_utimes(), kern_unlink(),
kern_chdir(), kern_chmod(), kern_chown(), kern_symlink(), kern_readlink(),
kern_select(), kern_statfs(), kern_fstatfs(), kern_stat(), kern_lstat(),
kern_fstat().
- Drop the unused 'uap' argument from spx_open().
- Replace a stale duplication of vn_access() in xenix_access() lacking
recent additions such as MAC checks, etc. with a call to kern_access().
copies arguments into the kernel space and one that operates
completely in the kernel space;
o use kernel-only version of execve(2) to kill another stackgap in
linuxlator/i386.
Obtained from: DragonFlyBSD (partially)
MFC after: 2 weeks
directly. This removes a few more users of the stackgap and also marks
the syscalls using these wrappers MP safe where appropriate.
Tested on: i386 with linux acroread5
Compiled on: i386, alpha LINT
for unknown events.
A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".
options, status pointer and rusage pointer as arguments. It is up to
the caller to copyout the status and rusage to userland if needed. This
lets us axe the 'compat' argument and hide all that functionality in
owait(), by the way. This also cleans up some locking in kern_wait()
since it no longer has to drop locks around copyout() since all the
copyout()'s are deferred.
- Convert owait(), wait4(), and the various ABI compat wait() syscalls to
use kern_wait() rather than wait1() or wait4(). This removes a bit
more stackgap usage.
Tested on: i386
Compiled on: i386, alpha, amd64
- struct plimit includes a mutex to protect a reference count. The plimit
structure is treated similarly to struct ucred in that is is always copy
on write, so having a reference to a structure is sufficient to read from
it without needing a further lock.
- The proc lock protects the p_limit pointer and must be held while reading
limits from a process to keep the limit structure from changing out from
under you while reading from it.
- Various global limits that are ints are not protected by a lock since
int writes are atomic on all the archs we support and thus a lock
wouldn't buy us anything.
- All accesses to individual resource limits from a process are abstracted
behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return
either an rlimit, or the current or max individual limit of the specified
resource from a process.
- dosetrlimit() was renamed to kern_setrlimit() to match existing style of
other similar syscall helper functions.
- The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit()
(it didn't used the stackgap when it should have) but uses lim_rlimit()
and kern_setrlimit() instead.
- The svr4 compat no longer uses the stackgap for resource limits calls,
but uses lim_rlimit() and kern_setrlimit() instead.
- The ibcs2 compat no longer uses the stackgap for resource limits. It
also no longer uses the stackgap for accessing sysctl's for the
ibcs2_sysconf() syscall but uses kernel_sysctl() instead. As a result,
ibcs2_sysconf() no longer needs Giant.
- The p_rlimit macro no longer exists.
Submitted by: mtm (mostly, I only did a few cleanups and catchups)
Tested on: i386
Compiled on: alpha, amd64
- Return NULL instead of returning memory outside of the stackgap
in stackgap_alloc() (FreeBSD-SA-00:42.linux)
- Check for stackgap_alloc() returning NULL in ibcs2_emul_find();
other calls to stackgap_alloc() have not been changed since they
are small fixed-size allocations.
- Replace use of strcpy() with strlcpy() in exec_coff_imgact()
to avoid buffer overflow
- Use strlcat() instead of strcat() to avoid a one byte buffer
overflow in ibcs2_setipdomainname()
- Use copyinstr() instead of copyin() in ibcs2_setipdomainname()
to ensure that the string is null-terminated
- Avoid integer overflow in ibcs2_setgroups() and ibcs2_setgroups()
by checking that gidsetsize argument is non-negative and
no larger than NGROUPS_MAX.
- Range-check signal numbers in ibcs2_wait(), ibcs2_sigaction(),
ibcs2_sigsys() and ibcs2_kill() to avoid accessing array past
the end (or before the start)
systems where the data/stack/etc limits are too big for a 32 bit process.
Move the 5 or so identical instances of ELF_RTLD_ADDR() into imgact_elf.c.
Supply an ia32_fixlimits function. Export the clip/default values to
sysctl under the compat.ia32 heirarchy.
Have mmap(0, ...) respect the current p->p_limits[RLIMIT_DATA].rlim_max
value rather than the sysctl tweakable variable. This allows mmap to
place mappings at sensible locations when limits have been reduced.
Have the imgact_elf.c ld-elf.so.1 placement algorithm use the same
method as mmap(0, ...) now does.
Note that we cannot remove all references to the sysctl tweakable
maxdsiz etc variables because /etc/login.conf specifies a datasize
of 'unlimited'. And that causes exec etc to fail since it can no
longer find space to mmap things.
contain the filedescriptor number on opens from userland.
The index is used rather than a "struct file *" since it conveys a bit
more information, which may be useful to in particular fdescfs and /dev/fd/*
For now pass -1 all over the place.
Several of the subtypes have an associated vnode which is used for
stuff like the f*() functions.
By giving the vnode a speparate field, a number of checks for the specific
subtype can be replaced simply with a check for f_vnode != NULL, and
we can later free f_data up to subtype specific use.
At this point in time, f_data still points to the vnode, so any code I
might have overlooked will still work.
kern_sigprocmask() in the various binary compatibility emulators.
- Replace calls to sigsuspend(), sigaltstack(), sigaction(), and
sigprocmask() that used the stackgap with calls to the corresponding
kern_sig*() functions instead without using the stackgap.
a follow on commit to kern_sig.c
- signotify() now operates on a thread since unmasked pending signals are
stored in the thread.
- PS_NEEDSIGCHK moves to TDF_NEEDSIGCHK.
prevent the compiler from optimizing assignments into byte-copy
operations which might make access to the individual fields non-atomic.
Use the individual fields throughout, and don't bother locking them with
Giant: it is no longer needed.
Inspired by: tjr
pointer types, and remove a huge number of casts from code using it.
Change struct xfile xf_data to xun_data (ABI is still compatible).
If we need to add a #define for f_data and xf_data we can, but I don't
think it will be necessary. There are no operational changes in this
commit.
on a process's pending signals, use the signal queue flattener,
ksiginfo_to_sigset_t, on the process, and on a local sigset_t, and then work
with that as needed.
constants VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS, USRSTACK and PS_STRINGS.
This is mainly so that they can be variable even for the native abi, based
on different machine types. Get stack protections from the sysentvec too.
This makes it trivial to map the stack non-executable for certain abis, on
machines that support it.
in their library (STYP_LIB) section.
- Attempt to make the code which calculates the next entry and
string offsets look clearer.
PR: kern/42580
Tested by: Olaf Klein <ok@adimus.de> (on 4.7-PRERELEASE)
